Specific sales figures were not divulged, and Chart-Track does not track digital sales, but the firm added that 82 percent of total Mario Kart 8 sales in the UK came through the Mario Kart 8 bundle. In addition, Mario Kart 8 recorded the best-selling first week for any Wii U game since the platform's launch in the UK in 2012.

Overall, Mario Kart 8 was the second best-selling game of the week, only behind Ubisoft's Watch Dogs, which is the fastest selling game in Ubisoft's history. Notably, Watch Dogs launched for five platforms (Xbox 360, Xbox One, PlayStation 3, PlayStation 4, and PC), while Mario Kart 8 is a Wii U-exclusive.

Watch Dogs has now crushed the first-week UK sales record for a new IP, with unit sales 58 percent better than past record-holder L.A. Noire (2011). The game also outperformed Assassin's Creed III (2012) by 17 percent to become Ubisoft's biggest launch in the UK. The game also helped move hardware, as the special Watch Dogs PS4 bundle accounted for more than 53 percent of PS4 hardware sales during the week. Overall, GFK Chart-Track's data for the week also showed that PS4 hardware in the UK rose 94 percent week-over-week.

Nintendo has not announced official Mario Kart 8 sales yet. Next week, the NPD Group is expected to disclose US industry sales for May, but because Mario Kart 8's release came on May 30, this report will only count two days' worth of sales.